------ Day 2 -------
The rails' "button_to" can add a button to the html file instead of using the tag. The rails' "link_to" method can be used to conveniently add a link to html file.
------ Day 3 ------- We can use redirect_to to navigate to a page after a form is submitted.
flash: a built-in Rails method (put in in layouts/application.html.erb) to pass information in one page to another.
Remember: For bootstrap's dismissable alerts to work, we need to update our Rails gems if we use Rails 5.1.0 or later. Use Command + Shift + V to "nicely" paste codes with auto-corrected indentation. TWBSColor: used to customize nav-bar
------ Day 4 ------- In Rails, an integer data type can only be 4-digit long.
You want to keep your Model class fat and your controller small.
db:drop => delete the whole database db:seed => use to add more information to our database
------ Day 5 -------
In ruby, everything is true, except nil and false (boolean value). && only moves forward in condition(s) if the previous condition is true. || onlue moves forward in condition(s) if the previous condition is false.
condition moves left to right nil && 77 || "ghost" => false because (nil && 77 is false, and Ruby ignores the rest of the condition)
No double quotation marks "" in SQL commands!!!